make (one’s) bones

make (one’s) bonesv.— «Chertoff—described as being “as cold-blooded as they come”— has a personal agenda that includes becoming U.S. Attorney General and, eventually, grabbing a seat on the U.S. Supreme Court. But there’s a problem for Chertoff with conservative Republicans—he happens to be pro-choice. So, taking the DHS job is Chertoff’s way to “make his bones,” as they say in Jersey, and grab headlines as a hard-line persecutor of “the towel-heads” to please the right and neutralize his abortion stance.» —“Mike Chertoff’s Dirty Little Secrets” by Doug Ireland Common Dreams Jan. 12, 2005. (source: Double-Tongued Dictionary)